Stochastics: An International Journal of Probability and Stochastic Processes
(Taylor and Francis)
•21 Jul 2021
Statistical causality and purely discontinuous local martingales
Valjarević, Dragana • Petrović, Ljiljana
Abstract
The statistical concept of causality in continuous time between
filtered probability spaces considered in this paper is based on
Granger’s definition of causality. The given concept of causality can
be connected to the purely discontinuous property for martingale
and filtration. If M is a purely discontinuous local martingale with
respect to purely discontinuous filtration (Gt), we prove that M will
remain purely discontinuous local martingale with respect to an
extension (Ft) of the filtration (Gt) if and only if (Gt) is its own cause
within (Ft). Moreover, we give conditions for a natural filtration of
the purely discontinuous martingale Xt to be a purely discontinuous
filtration, using the property of causality. We also, consider the connection
between the concept of statistical causality and the weak
predictable representation property for purely discontinuous local
martingales.
Abstract
The statistical concept of causality in continuous time between filtered probability spaces considered in this paper is based on Granger’s definition of causality. The given concept of causality can be connected to the purely discontinuous property for martingale and filtration. If M is a purely discontinuous local martingale with respect to purely discontinuous filtration (Gt), we prove that M will remain purely discontinuous local martingale with respect to an extension (Ft) of the filtration (Gt) if and only if (Gt) is its own cause within (Ft). Moreover, we give conditions for a natural filtration of the purely discontinuous martingale Xt to be a purely discontinuous filtration, using the property of causality. We also, consider the connection between the concept of statistical causality and the weak predictable representation property for purely discontinuous local martingales.